1. Field of the Invention
The present invention is related to an improved structure for introducing the open air into the engine room of a vehicle.
2. Related Art
A conventional construction juxtaposes a radiator, a cooling fan, an engine in order in a bonnet of a tractor and supplies the air from a front grille to the engine through the radiator and the cooling fan. Also, such construction may have the grille, covered with a dustproof net, at the side surface of the bonnet. In the above mentioned construction, an air cleaner is disposed in front of the radiator so as to take the unheated air before passing through the radiator.
In the conventional construction, the dustproof net must have as small meshes as possible in order to prevent dust from entering into the bonnet, however, small meshes reduce the air taken from a dustproof net. The grille must therefore cover a large area so as not to reduce the air taken in the bonnet and to keep dust away from the inner of a bonnet. Then the grille must be extended to the side of the bonnet. However, the grille cannot extend beyond the cooling fan so as to prevent the air from flowing to the engine. If the grille is disposed in the rear of the cooling fan, it will interrupt the course of the air because the air will also be introduced from the rear of the cooling fan. As mentioned above, in the conventional construction it is difficult to introduce sufficient volume of air while preventing dust from entering into the grille because of the limitation of the space for disposing the dustproof net.
Also when the air cleaner is disposed in front of the radiator, the bonnet tends to be too long to make a compact vehicle. It is desired that the air cleaner be disposed at the exhaust space on the engine and the air supplied into the air cleaner before being heated by the radiator.